在vue2时代，$refs 直接操作子组件
代码语言：javascript复制this.$refs.gridlayout.$children[index];虽然不推荐这么做，但是确实非常好用。但是vue2快速迁移到vue3，之前的这个写法因为干进度，不想重构，直接搬迁，发现不行？
看了下官方的文档：https://v3.cn.vuejs.org/guide/migration/array-refs.html#迁移策略
代码语言：javascript复制<template>
<div v-for="item in list" :ref="setItemRef"></div>
</template>
<script setup>
let itemRefs = ref()
const setItemRef = el => {
if (el) {
itemRefs.push(el)
}
}
onBeforeUpdate(() => {
itemRefs = []
})
onUpdated(() => {
console.log(itemRefs)
})
</script>注意：
- itemRefs 不必是数组：它也可以是一个对象，其 ref 可以通过迭代的 key 被设置。
- 如有需要，itemRefs 也可以是响应式的，且可以被侦听。
在tsx 这个怎么弄呢？
TSX refs
网上的大部分教程都是 template 的
Typing Template Refs
代码语言：javascript复制const el = ref<HTMLInputElement | null>(null)普通元素
Typing Component Template Refs
代码语言：javascript复制import MyModal from './MyModal.vue'
const modal = ref<InstanceType<typeof MyModal> | null>(null)
const openModal = () => {
modal.value?.open()
}对于子组件，其实和 let timer: ReturnType<typeof setTimeout> = null; 类似。
如果不进行类型声明，modal 方法无法调用。 需要是as 魔法了
还有一个需要特别注意，就是子组件内容是暴露出来的，如果是 <script setup> 组件，是无法获取内容的，具体参看：
vue2升级vue3:单文件组件概述 及 defineExpos/expose https://www.zhoulujun.cn/html/webfront/ECMAScript/vue3/8872.html
Refs 获取子元素，并操作子元素
代码语言：javascript复制import { defineComponent, nextTick, onBeforeUpdate, onMounted, onUnmounted, ref } from 'vue';
import ChartWrapper from '@/components/chart-wrapper';
import props from './props';
import { AddChartType, PanelModel, IGridPos } from '@/typings';
import { DashboardModule, sortGridPanels } from '@modules/dashboard';
import { getPluginTypes, handleInitChartPlugin, handleInitDataSource } from '@/utils/dashboard';
import Loading from '@/components/loading';
import { GRID_COL_NUM, GRID_ROW_HEIGHT, GRID_ROW_MARGIN, initPanel } from '@/constants';
import { debounce } from 'lodash';
import { deepClone } from '@/utils';
import AddPanel from '@dashboard/grid-panel/add-panel';
import TabPanel from '@dashboard/tab-panel/index';
import { GridItem, GridLayout } from 'v3-grid-layout';
import 'v3-grid-layout/dist/style.css';
import './index.scss';
import Row from './Row';
import EventBus from '@/utils/eventBus';
export default defineComponent({
name: 'GridPanelPlugin',
props,
emits: ['ready', 'delete', 'mounted'],
setup(props, { emit }) {
const layout = ref<IGridPos[]>([]);
const gridLayout = ref<InstanceType<typeof GridLayout>>(null);
const gridItem = ref<InstanceType<typeof GridItem>[]>([]);
const dashboardPanel = ref<Element>(null);
onBeforeUpdate(() => {
gridItem.value = [];
});
function drag(e: DragEvent) {
const parentRect = dashboardPanel.value.getBoundingClientRect();
let mouseInGrid = false;
if (
((mouseXY.x > parentRect.left) && (mouseXY.x < parentRect.right))
&& ((mouseXY.y > parentRect.top) && (mouseXY.y < parentRect.bottom))) {
mouseInGrid = true;
}
if (mouseInGrid === true && (layout.value.findIndex(item => item.i === 'drop')) === -1) {
layout.value.push({
x: (layout.value.length * 2) % (GRID_COL_NUM || 12),
y: layout.value.length (GRID_COL_NUM || 12), // puts it at the bottom
w: 1,
h: 1,
i: 'drop',
});
}
const index = layout.value.findIndex(item => item.i === 'drop');
if (index !== -1) {
const el = gridItem.value[index];
el.dragging.data = { top: mouseXY.y - parentRect.top, left: mouseXY.x - parentRect.left };
const new_pos = el.calcXY(mouseXY.y - parentRect.top, mouseXY.x - parentRect.left);
if (mouseInGrid === true) {
gridLayout.value.dragEvent('dragstart', 'drop', new_pos.x, new_pos.y, 1, 1);
DragPos.i = String(index);
DragPos.x = layout.value[index].x;
DragPos.y = layout.value[index].y;
}
if (mouseInGrid === false) {
gridLayout.value.dragEvent('dragend', 'drop', new_pos.x, new_pos.y, 1, 1);
layout.value = layout.value.filter(obj => obj.i !== 'drop');
}
}
}
function dragend(e: DragEvent) {
// const parentRect = document.getElementById('dashboard-panel').getBoundingClientRect();
const parentRect = dashboardPanel.value.getBoundingClientRect();
let mouseInGrid = false;
if (((mouseXY.x > parentRect.left) && (mouseXY.x < parentRect.right))
&& ((mouseXY.y > parentRect.top) && (mouseXY.y < parentRect.bottom))) {
mouseInGrid = true;
}
if (mouseInGrid === true) {
gridLayout.value.dragEvent('dragend', 'drop', DragPos.x, DragPos.y, 1, 1);
layout.value = layout.value.filter(obj => obj.i !== 'drop');
// UNCOMMENT below if you want to add a grid-item
this.layout.push({
x: DragPos.x,
y: DragPos.y,
w: 1,
h: 1,
i: DragPos.i,
});
this.$refs.gridLayout.dragEvent('dragend', DragPos.i, DragPos.x,DragPos.y,1,1);
try {
this.$refs.gridLayout.$children[this.layout.length].$refs.item.style.display="block";
} catch {
}
}
}
return {
gridLayout,
gridItem,
dashboardPanel,
layout,
movedId,
inited,
isLayoutReady,
isShowEditRowDialog,
rowForm,
};
},
render() {
if (!this.inited) {
return (<Loading/>);
}
return (
<div
ref='dashboardPanel'
id='dashboard-panel'
class={'dashboard-panel flex-1'}>
<GridLayout
ref='gridLayout'
layout={this.layout}
col-num={GRID_COL_NUM}
row-height={GRID_ROW_HEIGHT}
is-resizabl={this.editable}
is-draggable={this.editable}
vertical-compact={true}
use-css-transforms={false}
margin={GRID_ROW_MARGIN}
on-layout-updated={this.handleLayoutUpdated}
on-layout-ready={this.onLayoutReady}
>
{
this.layout.map((item) => {
return (
<GridItem
ref={(el: any) => {
if (el) {
this.gridItem.push(el);
}
}}
{{...item}}
>
{chart}
</GridItem>
);
})
}
</GridLayout>
</div>
);
},
});当然，这个代码是抽离出来的。
这个vue3-grid-layout，自己写了弄了一版，https://github.com/zhoulujun/vue3-grid-layout
转载本站文章《vue2升级vue3: TSX Vue 3 Composition API Refs》, 请注明出处：https://www.zhoulujun.cn/html/webfront/ECMAScript/vue3/8873.html
